Application time and herbicide rate effects on weeds in oilseed rape (Brassica napus var. oleifera)

Abstract

Field trials were conducted in 2010 and 2011 to evaluate different application time of metazachlor (Butisan 400 SC) and dimethachlor (Teridox-500), and their rate effects on weeds in oilseed rape (OSR). The weed population was consisted of winter and summer annuals, some perennial weeds, and volunteer wheat. Veronica spp., Triticum aestivum, Camelina sativa and Alopecurus myosuroides infestations were heavy throughout the experimental areas in both years. Efficacy of PRE herbicides was lower in comparison with early POST herbicides; it was ranged from 77.8% (Teridox – 2.0 L/ha) in Bitola locality to 86.9% (Butisan – 3.5 L/ha) in Skopje locality. Efficacy of early POST herbicides was ranged from 88.3% (Teridox – 2.0 L/ha) in Bitola locality to 98.6% (Butisan – 3.5 L/ha) in Skopje locality. Control of prevailing weeds was ranged from 53% to 97%, and 66% to 100% with PRE and early POST herbicide treatments, respectively. Particularly high efficacy showed Butisan applied early POST at 2.5 and 3.5 L/ha, respectively which excellent controlled prevailing weeds in both localities. All applied herbicides showed high selectivity to OSR; no visual injuries were determined by any rates in both years. OSR grain yield of herbicides applied PRE was lower in comparison with their early POST application.